Sulfonic acid surface active agent and method of preparation



Paten tecl Apr. 10, 195i SULFONIC ACID SURFACE ACTIVE AGENT AND METHOD OF PREPARATION Glen W. Hedrick, Glen Ellyn, 111., assignor to E. F. Houghton and Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application February 24, 1949, Serial No. 78,227

12 Claims. 1

The present invention relates to novel surface active agents and more particularly, it relates to surface active agents having marked wetting properties, as well as other desirable properties, comprising a new type of chemical substance, namely, the water-soluble salts of an aroyl sulpho propionic acid ester as more fully described hereinafter. This application is a continuation in part of application Serial No. 626,438, filed November 2, 1945, and now abandoned.

The principal object of the invention is to provide surface active agents having outstanding wetting properties, which agents may be used Wherever such properties are desired, for example, in processing textile fibres and fabrics, leather, paper, and other fibrous materials, in cleaning processes, such as general household cleaning, material cleaning, dishwashing, and the like, and in frothing, emulsifying, emulsion breaking, notation, and other processes. The agents are especially useful to increase the water-absorptivity of fibrous or other materials and, therefore, the wetting agents of the invention may advantageously be used in the kier boiling of cotton, in the scouring of wool, in the boilingofi of rayon,.in dyebaths, in the production of .Sanforized cotton in the fat-liquoring of leather, in the treatment of paper, and the like.

Other objects, including the provision of a novel. method ofproducing the wetting agents of the invention, will be apparent from a con sideration of the specification and the claims.

As indicated above, the wetting agents of the present invention comprise the Water-soluble salts of certain aroyl sulpho propionic acid benzyl esters, the aroyl radical being defined as a radical of the type RCO where R is an aryl radical of the type hereinafter set forth.

The surface active agents of the present invention are represented by the formula:

where R1 is an aryl group selected from the group consisting of phenyl; monochlorophenyl; monoalkyl phenyl and monoalkyl monochlorophenyl; the alkyl groups of which contain from 1 to 9 carbon atoms; monoalkyl tolyl, the alkyl atoms; phenyl phenyl; phenyl chlorphenyl; cyclohexyl phenyl; cyclohexyl chlorphenyl; naphthyl; monochloronaphthyl; methyl naphthyl and tetrahydronaphthyl; where R2 is selected from the group consisting of hydrogen and alkyl groups containing from 1 to 5 carbon atoms; where R3 is selected from the group consisting of hydrogen and alkyl groups containing not more than 2 carbon atoms; the total number of carbon atoms in R2 plus R3 being no more than 5 and the total number of carbon atoms in R2 plus R3 plus any alkyl group on the aryl nucleus, R1, being no more than 10; where.

B is an ethylene group; and where M is a cation providing water-solubility to the product.

In the above formula, no attempt has been made to indicate to which of the two carbon atoms in the ethylene (B) group the sulpho group (-SO3M) is attached. The most practical chemical processes, however, for introducing the sulpho group into this ethylene linkage are believed to produce mixtures rather than pure alpha or pure beta derivatives. Generally, while the alpha derivative is believed to predominate, the location of the-sulpho group is immaterial since it must exert a similar hydrophilic action on the molecule either in the alpha or the beta position, and it is to be understood that both the alpha and beta compounds and mixtures thereof are within the scope of the invention.

As pointed out in connection with the formula, M is a cation rendering the compound watersoluble, for example, an alkali metal such as sodium or potassium, the ammonium radical, and the like.

The products of the present invention thus embody not only an aroyl group but also a definite number of exterior or external carbon atoms in the various R groups. As stated, these external carbon atoms must total no more than 10. Some or all of the external carbonatoms may be provided by R2, that is by an alkyl group containing not more than 5 carbon atoms and attached to the benzyl group or by R2 and R3 (totalling no more than 5 carbon atoms) when two alkyl groups are attached to the benzyl group. Some or all of the external carbon atoms may be provided by a substituted alkyl group or a substituted alkyl group and a methyl group attached to the aryl nucleus, and as indicated, these substituted groups may be an alkyl group containing from 1 to 9 carbon atoms when R1 is monoalkyl phenyl or monoalkyl monochlorphenyl or a methyl group and an alkyl group containing from 1 to 8 carbon atoms as when R1 is monoalkyl tolyl. It is relatively immaterial from the standpoint of the present invention whether any of the various alkyl groups mentioned is a straight or branched chain alkyl group. A chlorine atom may also be attached 3 to the phenyl or naphthyl nucleus (as when R1 is chlorphenyl, monoalkyl monochlorophenyl, phenyl chlorphenyl, cyclohexyl chlorphenyl or monochloronaphthyl) Without altering the properties of the compound significantly. Since no one alkyl group attached to the phenyl nucleus when R1 is monoalkyl phenyl or monoalkyl monochlorophenyl contains more than 9 carbon atoms, and since the total number of carbon atoms in R2 plus R3 is no more than 5, and thetotalnum ber of external carbon atoms on the compound totals no more than 10, for each aryl group (R1) employed, there is a definite range of carbon atoms that may be present in the groups (R2 or R2 plus R2) attached to the benzyl .P and vice versa. For example, if there are no allryl groups attached to the aryl nucleus (1. e. R1 is phenyl, monochlorophenyl, phenyl phenyl, cyclohexyl phenyl, naphthyl, monochloronaphthyl or tetrahydronaphthyl) the number of carbon atoms supplied by the alkyl group R2. (R3 being hydrogen) or the alkyl, groups R2 and R3 must be no more than 5; while if, for example, a nonyl group is attached to the aryl nucleus (1. e. R1 is nonylphenyl or nonylchlorphenyl) R3 is limited to hydrogen and R2 is limited to hydrogen or a methyl group.

While numerous specific compounds may be prepared by the methods hereinafter described corresponding to the formula given for the compounds of the invention, they will possess marked wetting properties, making them available for use as surface active agents in the various industrial fields. This is because such compounds embody the basic structure hereinbefore set forth and contain external carbon atoms within the stated limits, and the specific examples hereinafter set forth demonstrate the fact that such compounds possess marked wetting properties.

The compounds of the invention possessing wetting properties to the highest degree are those corresponding to the formula:

$03M R3 where R1 is monoalkyl phenyl, the alkyl group of which contains from 1 to 5 carbon atoms; where R2 is an alkyl group containing from 1 to 5 carbon atoms; where R3 is hydrogen; Where B and may be represented as follows:

R o o where R is an alkyl group containing from 1 to 5 carbon atoms; where R2 is an alkyl group containing from 1 to 5 carbon atoms; where the number of carbon atoms in R plus R2 is from 6 to 8, and where B and M are as stated. Preferably, R contains 3 to 4 carbon atoms, R2 contains 3 to 4 carbon atoms, and M is sodium. The products of the invention may be readily and economically prepared by condensing the desired aryl derivative reactive in a Friedel- Crafts acylation type of reaction, with the anhydride of a four carbon atom dicarboxylic aliphatic acid, i. e. maleic anhydride or succinic anhydride; esterifying the resulting acid; and then converting the ester into the sulpho derivative, as will be further discussed hereinafter. Another, but not preferred, method of preparing the products of the present invention is by condensing a half ester-half acid chloride of the fourcarbon atom dibasicacidwith the aryl derivative to provide the ester, and thenconverting the ester into the sulpho derivative.

In preparing the aroyl derivative, the desired aryl derivative furnishing not only the aryl nucleus, but also any substituted alkyl group, is reacted by a Friedel-Crafts acylation reaction with a molar equivalent of the anhydride. The

aryl derivative maylbe obtained from any source,

for instance from coal tar, petroleum, or from synthetic processes. For example, in the case of alkylated phenyl derivatives, these may be obtained by condensing benzene with an alkyl halide or with an aliphatic olefin by a preliminary Friedel-Crafts alky-lation reaction.

Examples of the :aryl derivativesthat may be used in the preparation of the aroyl derivatives in accordance with the present inventions are:

benzene; monochlorobenzene; the monoalkyl benzenes such as toluene, isopropyl benzene (cumene), secondary butyl benzene, n-butyl benzene, amyl benzene, hexyl benzene, n-octyl benzene, 2-octyl benzene, l-methyl l-ethylamylbenzene, nonyl benzene, l-propyl 1-methylamylbenzene, and thelike; the monoalkyl toluenes such as xylene, methyl isopropyl benzene (cymene), secondary butyl toluene, octyl toluene, and the like; the monoalkyl monochlorobenzenes such as chlorotoluene, chlorocumene, secondary bu-tyl chlorobenzene, nonyl chlorobenzene, and the like; phenyl benzene, phenyl chlorbenzene, cyclohexyl benzene, and cyclohexyl chlorbenzene, naphthalene,- monochloronaphthalene, methyl naphthalene and tetrahydronaphthalene.

The anhydride of the four carbon atom dicar boxylic aliphatic acid may be the unsaturated maleic anhydride or the saturated succinic anhydride. When' maleic anhydride is employed, the aroyl compound prior to sulphonation is an aroyl acrylic acid ester. Upon sulphite addition, the double bond is saturated and the product is-a water-soluble salt of a aroyl sulpho pr-opionic acid ester, wherein the $03M group'has become attached to one of the carbon atoms of the CH=CH-group, and a hydrogen atomto the 7 other. In the case of succinic anhydride, the aroyl derivative of proprioni-c acid is formed as a result of the Friedel-Crafts reaction and a hydrogen atom attached either to the alpha or beta carbon atom must be substituted by the sulpho group, as hereinafter described.

The reaction between the aryl derivative and and the anhydride to form the corresponding aroyl acrylic or propionic acid is brought about, as has been stated above, by a Friedel-Crafts acylation reaction, and any of the various expedients used in that type of reaction may be employed in the production of the aroyl compound. Advantageously, the condensation is brought about by condensing the aryl derivative with approximately a molar equivalent of the anhydride in a suitable, solvent with anhydrous or substantially anhydrous aluminum chloride. While the solvent employed may, in the case. of relatively low boiling phenyl derivatives, be an excess of the phenyl derivative, the use of a suitable inert solvent such as carbon disulphide, orthodi'chl'orobenzene, methylene chloride, ethylene chloride, and tetrachloroethane is preferred.

The aryl derivative and the anhydride may be mixed with the solvent and the aluminum chloride added thereto, preferably gradually over a period of time, or the aryl derivative may be mixed with a portion or all of the aluminum chloride and the anhydride and solvent may then be added, preferably gradually, followed by the addition of further amounts of aluminum chloride if required. Other procedures for bringing together the aryl derivative, the anhydride, the solvent, and the aluminum chloride may of course be used, if desired. For example, the aluminum chloride, anhydride, and solvent may be mixed and the aryl derivative gradually added thereto. The reaction, at least at the start, is exothermic and hydrogen chloride is evolved as the reaction proceeds. The reacting mixture is generally maintained at a temperature in the range from about 20 C. to about 65 C. by coolingat the start and by heating subsequently if necessary,

and it is advantageous toagitate the mixture during the reaction.

When the condensation is completed, which may be determined by cessation of the evolution of the hydrogen chloride, the mass may be poured into ice, water, and a small amount of mineral acid, keeping the mass cold as is the usual practice in the type of reaction, and the mixture may be agitated until the aluminum chloride complex is decomposed. The condensation product which is in solution in the solvent may then be separated from the aqueous phase and washed with water and mineral acid to remove the salts of aluminum.

The aroyl acrylic or propionic acid may be isolated by either extracting it from the solvent with a warm 5% soda ash solution or by removing the solvent by distillation. The acid may be purified by disolving it in a solution of a suitable alkali, such as soda ash, filtering to remove any insoluble material and precipitating the acid by the addition of mineral acid.

In one procedure, the aryl derivative is dissolved in an inert solvent and about one molecular equivalent of maleic anhydride is added to the solution. The mixture is heated to a temperature at which the aluminum chloride complex remains dispersed, for example, to about 40 C., and is maintained between that temperature and about 50 C. during the reaction. The aluminum chloride (about 2 molecular equivalents) is added gradually, for example, in portions during the reaction, and the mass is agitated during the reaction. When the reaction is complete, which may require several hoursfor example six hoursthe aluminum chloride complex is decomposed and the acid isolated as above described.

In a more preferred procedure, the aluminum chloride, anhydride, and a chlorinated solvent are mixed, and the mixture is agitated and becomes uniform. The aryl derivative is gradually added at a temperature between about 40 C. and about 50 0., and after the addition is completed the mixture is stirred for a short period at a temperature between about 40 C. and about 60 C. The aluminum chloride complex is decomposed and the acid isolated as above-described.

The aroyl acrylic or propionic acid is esterified with a compound providing the desired benzyl group, and the resulting benzyl ester is then converted to the sulpho derivative. The ester of the acid may be prepared by any of the suitable esterifying reactions.

In one type of method, the ester may be formed by reacting the acid with one molecular equivalent of the benzyl alcohol containing the R2 and R3 groups as described corresponding to the henzyl ester desired in the presence of a solvent and an esterifying catalyst such as concentrated sulphuric acid, benzeneor toluene-sulphom'c acid. Preferably, the solvent is one which like toluene, boils slightly abovethe boiling point of water. The mixture of the aroyl acrylic or propionic acid, the benzyl alcohol, the solvent and the esterification catalyst are boiled and the water formed by the esterification reaction is removed. After the esterification reaction has been completed, the ester, which is in solution in the solvent, may be washed with water, followed in some cases by dilutealkali to remove any unconverted acid and the traces of catalyst. The ester may be isolated by removing the solvent by steam distillation at atmospheric pressure, or by evaporationin vacuo.

In another and preferred type of esterification procedure, the benzyl ester of the aroyl acrylic or propionic acid may be obtained by dissolving the acid in a solvent such as toluene, benzene, isopropanol, ethanol, butanols, acetone, methyl ethyl ketone, dioxane, carbon tetrachloride, and the like. The acid is then converted into a salt and the desired benzyl ester formed by reaction with benzyl chloride or the appropriate alkylated benzyl chloride containing the R2 group or the R2 and R3 groups as described. In such a process, the salt is advantageously formed by the addition of a slurry of soda ash in water, and in such a case, foaming occurs due to the evolution of carbon dioxide, and the mass may become thick and may have the appearance of a clear gel. The reaction between the salt of, the acid and the benzyl chloride is slow and refluxing for a number of hours is generally required. When the esterification has been completed, the precipitated salt is filtered oif or washed out with water and the benzyl ester is obtained upon removal of the solvent by steam or vacuum distillation.

The aroyl acrylic or propionic acid benzyl ester may be converted into the sulpho derivative by any process by which the SO3M group may be attached to one of the carbon atoms of the vinylene or ethylene chain of the acrylic or propionic acid ester. Preferably, when an aroyl acrylic acid ester is employed, the sulphonation is brought about by reactin the ester with a bisulphite such as sodium, potassium, or ammonium bisulphite. In the sulphonation reaction, the ester is mixed with the bisulphite dissolved in water or other solvent, for example, a mixture of equal parts of water and ethyl alcohol. The bisulphite employed is sufiicient to convert the ester into the sodium or other salt of the sulphonic acid, the use of a slight excess of the bisulphite often being advantageous. The mixture is advantageously heated in a closed container equipped with an agitator until the ester becomes completely soluble in water. The temperature of heating will depend on the particular ester being treated and usually a temperature between about C. and C. will be employed, and in many instances it will be desirable to heat the mixture to boiling. The ester is rendered completely soluble in water by thi treatment and the product formed is the sulphonic acid salt of the cation of the bisulphite. Thus, as stated in connection with the formula, M may be any cation which provides water-solubility, for example, an alkali metal ion, ammonium radical, or the like.

l pound gave a wetting speed of 120 seconds and j at a concentration of 0.25% a Wetting speed of 40 seconds.

EXAMPLE 4 The salt of the amyl benzyl ester of chlorbenzoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing monochlorbenzene with maleic anhydride. The chlorbenzoyl acrylic acid thus formed was converted to its sodium salt and esterified with amyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 50 seconds at a concentration of 0.1% and a wetting speed of 19 seconds at a con centration of 0.25

EXAMPLE 5 The salt of the benzyl ester of. toluoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing toluene with maleic anhydride. The toluoyl acrylic acid thus formed Was converted to its sodium salt and esterified with benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 100 seconds at a concentration of 0.1% and a wetting speed of 20 seconds at a concentration of 0.25%.

EXAMPLE 6 The salt of the benzyl ester of ethyl benzoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing ethyl benzene with maleic anhydride. The resulting ethyl benzoyl acrylic acid was converted to its sodium salt and esterified with benzyl chloride, and the resultin ester was reacted with sodium bisulphite to form the sulpho compound. The compound gave a wetting speed of 60 seconds at a concentration of 0.2%.

EXAMPLE '7 The salt of the benzyl ester of sec-butyl chlorbenzoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing sec-butyl chlorbenzene with maleic anhydride. The resulting sec-butyl chlorbenzoyl acrylic acid thus formed was converted to its sodium salt and esterified with benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 25 seconds at a concentration of 0.1%.

EXAMPLE 8 The salt of the isopropyl benzyl ester of methyl benzoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing methyl benzene with maleic anhydride. The resulting methyl benzoyl acrylic acid was converted to its sodium salt and esterified with isopropyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 16 seconds at a concentration of 0.1

EXAMPLE 9 The salt of the methyl benzyl ester of sec-butyl benzoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first con densing sec-butyl benzene with'maleic anhydride; The sec-butyl benzoyl acrylic acid thus formed was converted to its sodium salt and esterified with methyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 15 seconds at a concentration of 0.1

EXAMPLE 10 The salt of the amyl benzyl ester of toluoyl sulpho propionic acid was prepared, followingthe procedure of Example 1, by first condensing tolu- The toluoyl acrylic ene with maleic anhydride. acid thus formed was converted to itssodium salt and esterified with amyl benzyl chloride, and

the resulting ester was reacted with sodium bisulphite to form the sulpho derivative.v The compound gave a wetting speed of 25 seconds at a concentration of 0.1% and a wetting speed of 8 seconds at a concentration of 0.25%.

EXAMPLE 12 The salt of the isopropyl benzyl ester of isopropyl benzoyl (cumenoyl) sulpho propionicacid was prepared, following the procedure of Example 1, by first condensing cumene with maleic anhydride. The cumenoyl acrylic acid thus formed was converted to its sodium salt and esterified with isopropyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 3 seconds at a concentration of 0.1%.

EXAMPLE 13 The salt of the isopropyl benzyl ester of secbutyl benzoyl sulpho propionic acid was prepare following the procedure of Example 1, by first condensing sec-butyl benzene with maleic anhydride. The sec-butyl benzoyl acrylic acid thus formed was converted to its sodium'salt and esterified with isopropyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of. 3 seconds at a concentra tion of 0.1%.

EXAMPLE. 14'

The salt of the sec-butyl benzyl ester of isopropyl. benzoyl (cumenoyl) sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing cumene with maleic anhydride. vThe cumenoyl acrylic acid thus formed was converted to its sodium salt and esterified with sec-butyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 2 seconds at a concentration of 0.1%.

EXAMPLE 15 The salt of the sec-butyl benzyl ester of isopropyl toluoyl sulpho propionic acid was prepared, following the procedure of Examplel, by' first condensing cymene with maleic anhye dride. The cymenoyl acrylic acid thus formed was converted to its sodium salt and esterified 1 l with sec-butyl benzyl'chloride, and the resulting ester with reacted with sodium bisulphiteto form the sulpho derivative. The compound gave a wetting speed 'of'2 seconds at a concentration of 0.1% and a wettin speed of instantaneous at a concentration of 0.25%.

EXAMPLE 16 The-salt of thesec-butyl benzyl-esterof-secbutyl benzoyl sulpho propionic acid with prepared, following the procedure of Example 1, by first condensing 'sec-zbutyl benzene with maleic anhydride; The sec-butyl'b'enzoyl acrylic acid thus formed was converted to its sodium salt andesterified with sec-butyl benzyl chloride,.

and the resulting ester was reacted with sodium bisulphite to formthe sulpho derivative. The

compound gave a wetting speed of i2-seconds at a concentration of 0.1%.

EXAMPLE 17 1 The salt of .thediethyl benzyl ester ofsecbutyl benzoyl sulpho propionic acid was prepared,

following the procedure of Example 1, by first condensing sece'but'yl benzene with maleic anhydride. The sec-butyl 'benzoyl acrylic acid thus formed was converted to its sodium salt and esterified with diethyl benzyl chloride, and the resultin'g'ester was reacted'with sodium bisulphite to iformthe sulpho derivative. The compound gave a wetting speed of 4 seconds at-a concentr'a-- tion of 0.1%.

EXAMPLEIQ...

The salt of the ethyl benzyl'ester of sec-amyl benzoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing sec-amyl: benzene with' maleic anhydrides. ThBTSE'O-EIHYI' benzoyl acrylic 'acid thus formed was. converted to;its sodium salt-and esterified with" ethyl benzyl chloride, and the resulting ester wasa'reacted with sodiumbisulphitetoform' theisulpho derivative; The com+ pound gave .a wetting speed of 2 secondsata concentration of $011 2- EXAMPLE 20 Thesalt of the benzyl ester oflnonyl benzoyl sulpho propionic. acid was prepared, following the procedure of Example. 'l, by, first condensing nonyl benzene with maleic anhydride. The nonyl b'enzoyl acrylic acid thus formed'was converted to' its sodium salt and esterified. with benzyl chloride, and the resulting ester was reacted with sodium bisulphite tofform the sulpho derivative; The compound gave a wetting speed of 35 seconds at a.concentration of 0 .1% and a wetting speed of IO'seconds at'a concentration (PO-25%;

EXAMPLE '21 The saltof the sec-amyl benzyl;ester"of:secbutyl. benzoyl sulpho propionicv acid. was pre-- pared, following the procedure; of Example 1 by first condensing sec-butyl benzene with maleic anhydride. The sec-butyl benzoyl acrylic acid thus formed was converted to its sodium salt and esterified with sec-amyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form. the sulpho derivative. The compound gave a wetting speed of 17 seconds at a concentration of 0.1%.

EXAMPLE 22 The'salt ofrthe sec-butyl benzyl ester of secamyl benzoyl sulpho 'propionic acid was prepared, following the procedure of Example 1, by condensing sec-amyl benzene with maleic anhydride; The sec-amyl benzoyl acrylic'acid thus formed was converted to its sodium salt and esterified with sec-butyl benzyl chloride, and the resulting ester was vreacted with sodium bisulphite to form the sulpho derivative. The com- "pound gave a wetting speed of 6 seconds at a concentration of 0.1%.

EXAMPLE 23 The salt of the methylbenzyl ester of octyl toluoyl sulpho propionic acid was prepared, following the procedure vof Example 1, by first condensing octyl toluene with maleic anhydride. The octyl toluoyl acrylic acid thus formed was converted to its sodium saltand esterified with methyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 35 seconds at a concentration of 0.1% and a wetting speed of 8 seconds ,at a concentration of 0.25%. 7

EXAMPLE 24 The salt of the benzyl ester of phenyl benzoyl sulpho 'propionic acid was prepared, following the procedure of Example 1, by first condensing phenyl benzene with maleic anhydride. The phenyl benzoyl sulpho propionic acid thus formed was converted to its-sodiumsalt and esterified with benzyl chloride, and the resultingv ester was reacted with sodium bisulphite to form the sulpho derivative., The compound gave a wetting speed of..50.secondsat aconcentration of 0.1%.

EXAMPLE 25 The salt of t the butyl methyl benzyl ester of phenyl benzoyl sulpho propionc acid-was pre: pared, following the procedure of Examplel by first condensing phenyl benzene with ,maleic: anhydride. The phenyl benzoyl 'acrylicacidthus formed was converted .to its sodium salt and esterified with butyl methyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 12 secondsat a concentrationof 0.1% and a wettingspee-d of 3' seconds at a concentration of 0.25%.

EXAMPLE 26 The salt of the benzyl ester 'of 'cyclohexyl benzoyl sulpho propionic acid was prepared,'follow ing the procedure of Example 1, by first condensing cyclohexyl benzene with maleic anhydride. The cyclohexyl benzoyl acrylic acid thus formed was converted to its. sodium salt and esterified with benzyl chloride, and the resulting ester was, reacted with sodium bisulphite to iorm the sulpho derivative. The compound gave, a Wetting speed oi 49 $99Ild$ at a concentratlon of 0.1%.

The salt of the benzyl ester of chlornaphthoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing monochlornaphthalene with maleic anhydride.

The chlornaphthoyl acrylic acid thus formed was converted to its sodium salt and esterified with benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 32 seconds at a concentration of 0.1% and a wetting speed of 11 seconds at a concentration of 0.25%.

EXAMPLE 29 The salt of the isopropyl benzyl ester of naphthoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing naphthalene with maleic anhydride.

Ihe naphthoyl acrylic acid thus formed was converted to its sodium salt and esterified with isopropyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 12 seconds at a concentration of 0.1%.

EXAIWPLE 30 The salt of the methyl benzyl ester of methyl naphthoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing methyl naphthalene with maleic anhydride. The methyl naphthoyl acrylic acid thus formed was converted to its sodium salt and esterified with methyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 30 seconds at a concentration of 0.1%.

EXAMPLE 31 The salt of the propyl ethyl benzyl ester of methyl naphthoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing methyl naphthalene with maleic anhydride. The methyl naphthoyl acrylic acid thus formed was converted to its sodium salt and esterified with propyl ethyl benzyl chloride, and the resulting ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 10 seconds at a concentration of 0.1% and a wetting speed of 3 seconds at a concentration of 0.25%.

EXAMPLE 32 The salt of the benzyl ester of tetrahydronaphthoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing tetrahydronaphthalene with maleic anhydride. The tetrahydronaphthoyl acrylic acid thus formed was converted to its sodium salt and esterified with benzyl chloride, and the resulting 14 ester was reacted with sodium bisulphite to form the sulpho derivative. The compound gave a wetting speed of 30 seconds at a concentration of 0.1% and a wetting speed of 8 seconds at a concentration of 0.25%.

EXAMPLE 33 The salt of the sec-butyl benzyl ester of tetrahydronaphthoyl sulpho propionic acid was prepared, following the procedure of Example 1, by first condensing tetrahydronaphthalene with maleic anhydride. The tetrahydronaphthoyl acrylic acid thus formed was converted to its sodium salt and esterified with sec-butyl benzyl chloride, and the resulting ester was reacted with sodium bisulphiteto form the sulpho derivative. The compound gave a wetting speed of 5 seconds at a concentration of 0.1%.

,Of the foregoing compounds, the water-soluble salts of the butyl benzyl esters of the butyl benzoyl sulpho propionic acids and more specifically the sodium salt of the sec-butyl benzyl ester of sec-butyl benzoyl. sulpho propionic acid; the water-soluble salts of the butyl benzyl esters of the propyl benzoyl sulpho propionic acids and more specifically the sodiumsalt of the sec-butyl benzyl esters of isopropyl benzoyl sulpho propionic acid; and the water-soluble salts of the propyl benzyl esters of the propyl benzoyl sulpho propionic acid and more specifically the'sodium salt of the isopropyl benzyl ester of the isopropyl benzoyl sulpho propionic acid, are preferred.

Considerable modification is possible in the method of preparing the compounds as well as in selecting the various combinations of R1, R2, R3,

and. M without departing from the scope of the invention.

I claim:

1. As a surface-active agent possessing marked wetting properties, a water-soluble salt of an aroyl sulpho propionic acid ester corresponding to the formula:

$03M R3 where R1 is an aryl group selected from the group consisting of phenyl; monochlorophenyl; monoalkyl phenyl and monoalkyl monochlorophenyl, the alkyl groups of which contain from 1 to 9 carbon atoms; monoalkyl tolyl, the alkyl group of which contains from 1 to 8 carbon atoms; phenyl phenyl; phenyl chlorphenyl; cyclohexyl phenyl; cyclohexyl chlorphenyl; naphthyl; monochloronaphthyl; methyl naphthyl and tetrahydronaphthyl; where R2 is selected from the group consisting of hydrogen and alkyl groups containing from 1 to 5 carbon atoms; where R3 is selected from the grou consisting of hydrogen and alkyl groups containing not more than 2 carbon atoms; the total number of carbon atoms in R2 plus R3 being no more than 5 and the total number of carbon atoms in R2 plus R3 plus any alkyl group on the aryl nucleus, R1, being no more than 10, where B is an ethylene group, and wherein M is a cation providing water-solubility to the product.

2. The product of claim 1 wherein M is sodium.

3. As a surface-active agent possessing marked wetting properties, a water-soluble salt of a benzoyl sulpho propionic acid ester corresponding to .the formula:

where R1 is a monoalkyl phenyl group, the alkyl groupof which contains from 1' to-L5 carbon atoms;

wetting properties, the sodium salt of a butyl benzyl ester of butyl benzoyl sulpho propionic acid.

'7. As a surface-active agent possessing marked wettingproperties', the sodium salt of the secondary butyl benzyl ester of secondary'butyl benzoyl sulpho propionic acid.

' 8. As a surface-active agent possessing marked wetting properties, the sodium salt of a propyl benzyl ester of butyl benzoyl sulpho propionic acid.

9. As a surface-active agent possessing marked wetting properties, the sodium saltof the isopropyl benzyl ester .of secondary butyl' benzoyl sulpho propionic acid.

10. As a surface-active agent possessing marked wetting properties, the sodium salt of a butyl benzyl ester of 'propyl benzoyl sulpho propionic acid.

11. As a surface-active agent possessing marked wetting properties, the sodium salt of the secondary butyl benzyl ester of isopropyl benzoyl sulpho propionic acid.

12. The method of preparing a surface-active agent possessing marked wetting properties which comprises condensing in a Friedel-Crafts acylation reaction, an aryl derivative selected from the. group consisting of benzene; monochlorobenzene; monoalkylbenzene and monoalkyl monochlorobenzene, the alkyl groups of which contain from 1 to 9 carbon atoms; monoalkyl toluene, the alkyl group of which contains from 1 to 8 carbon atoms; phenyl benzene; phenyl chlorbenzene; cyclohexylbenzene; cyclohexyl chlorbenzene; naphthalene; monochloronaphthalene; methyl naphthalene and tetrahydronaphthalene with maleic anhydride to form the corresponding aroyl acrylic acid, esterifying the resulting acid with an esterifying compound providing an ester group selected from the group consisting of benzyl; monoalkyl benzyl, the alkyl group of which contains from 1 to 5 carbon atoms; and dialkyl benzyl, the alkyl groups of which containa total of not more than 5 carbon atoms, said esterifying compound being'selected to provide an esterigroup which provides, along with any alkyl group attached to said aryl nucleus, a total number of carbon atoms in alkyl groups of no more than 10; and reacting the resulting ester with sodium bisulphite, at a temperature between about C. and about 0., to form the sodium salt of the corresponding aroylsulpho propionic acid ester.

GLEN W. HEDRICK.

REFERENCES CITED The following references are of record in the file of this patent:

Bogert et al.: J. A. C. S., vol. 47, pp, 526-535 (1925). 

1. AS A SURFACE-ACTIVE AGENT POSSESSING MARKED WETTING PROPERTIES, A WATER-SOLUBLE SALT OF AN AROYL SULPHO PROPIONIC ACID ESTER CORRESPONDING TO THE FORMULA: 